1. Field of the Invention
The present invention relates to a shipping package for an ink jet recording head (hereinafter referred to as a recording head) to be mounted detachably on an ink jet recording apparatus, which is in sales mode usable for transport and storage in sealed state, as well as for selling, and more specifically to the transport and storage for a recording head cartridge which can be freely mounted on or demounted from an ink tank for storing the ink to be supplied to the recording head.
2. Related Background Art
An ink jet recording apparatus performs the recording of characters and images on the recording medium such as paper by discharging the liquid ink from the discharge orifices (discharge ports) of a recording head, in which the recording head for use on the recording apparatus is largely classified into two types: permanent and disposable.
The recording head of permanent type is one in which the head is already incorporated in the recording apparatus at the shipping of the apparatus, and can be replaced by the serviceman only when the apparatus breaks down. Such recording head of permanent type is frequently transported or stored with a cap placed over the discharge orifices of the recording head filled with the recording ink or preservation liquid.
Also, the recording head of disposable type can be further divided into an integral head cartridge having an ink tank for holding the ink to be supplied to the recording head integrally at any time, and a tank separable head cartridge having a tank holder as a tank mounting portion on the recording head, two of which are separable as required. In either case, the operator can replace the head by changing to a new cartridge as required.
For transportation and storage of the integral head cartridge, refer to, for example, Japanese Patent Application Laid-Open No. 3-176156 by the present applicant. In the above publication, there is disclosed a constitution in which the ink is filled within the tank, and the discharge orifices of the recording head and an atmosphere communicating opening provided on the ink tank are both sealed.
On the contrary, for transportation and storage of the separable head cartridge, there is known Japanese Patent Application Laid-Open No. 6-183028 by the present applicant, proposing that the head and the tank are separately provided, because if the head to be replaced is mounted with a replaceable tank and packaged as one piece, the evaporated ink constituents may stick to the contact portion with the recording head which is an electrical connection with the recording apparatus, resulting in degradation of the recording head. In the above publication, it is also disclosed that a humidity preserving member is used against evaporation through a gap between a head handling member and the head, and that the ink or preservation liquid is filled within the head, and the discharge orifices are sealed by a seal member and a cap member. Also, in the Japanese Patent Application Laid-Open No. 7-17056, there is disclosed a transport and storage method in which the head having the ink filled is contained in a sealed package having the inert gas filled.
On the other hand, a simple ink tank which holds the ink to be supplied to the recording head is proposed and practically used in which a negative pressure producing chamber for producing a negative pressure to the recording head and an ink reserving chamber for directly reserving the ink are integrated via a communicating portion, in order to increase the ink storing efficiency and the use efficiency of the ink tank.
The examples are Japanese Patent Application Laid-Open No. 7-125232, disclosing an invention that a negative pressure producing member around an atmosphere communicating opening to be tightly enclosed is made an area where the ink is not held, and Japanese Patent Application Laid-Open No. 6-40043, disclosing an invention of a partition wall having a structure for promoting the exchange between the air and the liquid. In the above publication, there is also disclosed a simple ink tank in sales form for sealing both an atmosphere communicating opening for communicating the inside of a negative pressure producing chamber to the atmosphere and an ink supply opening for supplying the ink to the outside such as a recording head, which is an excellent invention.
By the way, the ink jet recording apparatus is demanded with the capability of recording on various recording media at higher precision in recent years.
Therefore, the number of ink tanks to be mounted on the recording apparatus, as well as the kinds of ink to be reserved within the tank, tend to increase, and correspondingly, the tank separable head cartridges as above mentioned with the ability of mounting in one cartridge a plurality of ink tanks at the same time are increasing. Also, in order to reduce the number of replacing the replaceable ink tank, the ink tank itself tends to be bigger. Therefore, since the mounting portion for the replaceable ink tank becomes bigger, the occupied size of head cartridge itself increase.
On the other hand, in such recording apparatus, in order to increase the amount of reserving the ink to reduce the number of replacements and accomplish more compactness, it is desirable to adopt a structure having an ink reserving portion for directly reserving the ink, such as one having a negative pressure producing chamber and an ink reserving chamber integrated in the replaceable ink tank.
Such a large-sized head cartridge, with the discharge orifices sealed with well-known sealing means consisting of a seal member and a cap, like the conventional art, and having the ink filled inside thereof, was sealingly packaged in a blister pack, as described in Japanese Patent Application Laid-Open No. 3-176156, in which there was a phenomenon that the discharge performance was depressed in the early stage of use. In particular, this phenomenon was remarkably seen with the head for discharging small droplets of 20 pl or less.
The present inventors found, as a result of elucidating this cause, that the inside of the head was less hydrophilic than the conventional head cartridge, and due to this decrease in hydrophilic property, the discharge of small droplets was affected. And as a result of examining the cause of decrease in hydrophilic property, they reached a conclusion that there is a bad factor in the interrelation between the capacity of a sealed package such as a blister pack, and the content volume of head where the ink is filled. Accordingly, based on this knowledge, they recognized that it was important to propose the sales form of optimal recording head.
On the other hand, if a head cartridge having mounted the ink tank as above described as a replaceable tank for the head cartridge on the tank holder and sealed the discharge orifices of the recording head with well-known sealing means was sealingly stored within a blister pack, there was a new problem that the leakage of ink occurs from the discharge orifice face, due to expansion of the gas within the ink tank tightly closed.